The long term objectives of this study are to explore the utility of defining binge-eating episodes in bulimia nervosa by the amount of food consumed and to reveal factors that contribute to the development or maintenance of bulimic symptoms. An additional objective is to improve the recognition of an alternative symptom cluster that resembles bulimia nervosa-purging subtype, except that perceived binge episodes do not involve objectively large amounts of food. Recent research indicates that a substantial number of young women suffer from this alternative symptom cluster (subjective bulimia nervosa-SBN) suggesting that SBN represents a significant public health concern. One specific aim of this study is to test the hypothesis that, like women with DSM-IV bulimia nervosa, women with SBN demonstrate clinically significant levels of distress and impairment. A second aim is to demonstrate that SBN is distinct from DSM-IV bulimia nervosa and thus should not be combined with this syndrome within one diagnostic category. The study proposes to extend preliminary data suggesting that women with bulimia nervosa have higher levels of impulsiveness compared to women with SBN. In addition, this study proposes a novel examination of whether, compared to women with SBN, women with bulimia nervosa demonstrate lower levels of satiety and blunted cholecystokin (CCK) release following a rest meal. The study will include 30 women with DSM-IV bulimia nervosa-purging subtype, 30 women with SBNm and 30 non-eating disordered control females. Subjects will complete psychological assessments including structured clinical interviews and standardized questionnaire assessments of depression, anxiety, impulsiveness, and social and occupational functioning. Subjects will also participate in assessments of post-prandial satiety and CCK release. This study will test a model of bulimia nervosa in which deficient satiety signals fail to decrease the impulse to eat which, combined with poor impulse control, increases the liability to experience objectively large binge-eating episodes by the amount of food consumed and reveal etiologic or maintaining factors for objectively large bing episodes in bulimia nervosa. Further, this study has the potential to identify a new subtype of eating disorder that is worthy of study, treatment, and inclusion in nosological schemes.